On 14 Mar 2014 18:30, "Paulo Pinto" <pj...@progtools.org> wrote:
>
> Am 14.03.2014 19:06, schrieb Iain Buclaw:
>>
>> On 14 March 2014 17:53, Walter Bright <newshou...@digitalmars.com> wrote:
>>>
>>> On 3/14/2014 10:26 AM, Johannes Pfau wrote:
>>>>
>>>>
>>>> I use manifest constants instead of version identifiers as well. If a
>>>> version identifier affects the public API/ABI of a library, then the
>>>> library and all code using the library always have to be compiled with
>>>> the same version switches(inlining and templates make this an even
>>>> bigger problem). This is not only inconvenient, it's also easy to think
>>>> of examples where the problem will only show up as crashes at runtime.
>>>> The only reason why that's not an issue in phobos/druntime is that we
>>>> only use compiler defined versions there, but user defined versions are
>>>> almost unusable.
>>>
>>>
>>>
>>> Use this method:
>>>
>>>
>>> --------
>>> import wackyfunctionality;
>>> ...
>>> WackyFunction();
>>> --------
>>> module wackyfunctionality;
>>>
>>> void WackyFunction() {
>>> version (Linux)
>>> SomeWackyFunction();
>>> else version (OSX)
>>> SomeWackyFunction();
>>> else
>>> ... workaround ...
>>> }
>>> --------
>>
>>
>>
>> Some years down the line (and some platform testing) turns into:
>>
>> --------
>> module wackyfunctionality;
>>
>> void WackyFunction() {
>> version (Linux) {
>> version (ARM)
>> _SomeWackyFunction();
>> else version (MIPS)
>> MIPS_SomeWackyFunction();
>> else version (X86)
>> SomeWackyFunction();
>> else version (X86_64)
>> SomeWackyFunction();
>> else
>> ... should be some wacky function, but workaround for general
case ...
>> }
>> else version (OSX) {
>> version (PPC)
>> iSomeWackyFunction();
>> else
>> SomeWackyFunction(); // In hope there's no other Apple
hardware.
>> }
>> else version (OpenBSD) {
>> /// Blah
>> }
>> else version (Haiku) {
>> /// Blah
>> }
>> else
>> ... workaround ...
>> }
>> --------
>>
>
>
> That is why the best approach is to have one module per platform specific
code, with a common interface defined in .di file.
>
Don't tell me, tell the druntime maintainers. :)
